This invention relates to apparatus for frying foods and particularly to improved deep fat fryers wherein fat heated externally of the fryer vessel or tank is recirculated therethrough. The invention is discussed in and was developed in conjunction with the fryer invention of U.S. Pat. No. 4,487,691 issued to Robert Panora on Dec. 11, 1984, which patent is incorporated herein by reference.
Deep fat frying of foods such as potatotes, fish, meats, and pastries is performed by immersing the foods in a tank containing heated cooking oil or fat. Of considerable importance in such fryers are their systems for heating the fat and for maintaining its temperature uniformity and cleanliness.
Of as great importance is the fryer's productivity, not only during actual frying operation, but also in enabling quick start-up at the beginning of the day or whenever the unit has fat replaced during the day. This invention was specifically designed for the fat recirculation, external heat-exchanger-type fryer illustrated in the aforementioned U.S. Pat. No. 4,487,691, and has considerably reduced its start-up time from what it had been prior to its incorporation into the design.
Accordingly, it is an object of the invention to provide quick start-up in a heat-exchanger-type fryer. This is accomplished by providing a novel cleaning and drying method and apparatus which eliminates what has been discovered to be a key factor causing long starting times. That factor was water left in the recirculation system from a previous rinse. The effect of that water was to create pump vapor lock when next starting the fryer, preventing or inhibiting fat recirculation. Not only was start-up delayed, but the potential of overheated fat standing unrecirculated in the heat exchanger could easily damage the fat and reduce its useful life.
Specifically, the invention has as a primary object the intermittent or pulsed operation of the burner for the heat exchanger, when it is theoretically empty after cleaning and flushing, but still contains residual rinse water therein, in order to flash off residual water droplets in a rapid and efficient manner without damage to the heat exchanger. By drying the heat exchanger internally immediately upon cleaning, start-up time upon replacement of the fat has been reduced considerably from what it was prior to introduction of the invention.